Relay and amplifier



July 7, 1 25. 1 ,545,153

' J. T. M DERMOTT.

RELAY AND AMPLIFIER Filed Dec. 27, 1921 2' shuts-sheet 1 mum:

July 7, 1925. 1.545.153

J. r. MCDERMOTT:

RELAY AND AMPLIFIER Filed Dec. 27,- 1921 2 Sheets-Sheet 2 Patent July 7, "i195.

UNITED STATE JAMES T. MQDERMOTT, OF WORCESTER, MASSACHUSETTS.

. RELAY AND AMPLIFIER.

Application filed December 27, 1921. Serial No. 524,871.

To all whom it my concern:

Be it known that I, JAMES T. MCDERMOTT a citizen of the United States, residing at Worcester in the county of Worcester and State of Massachusetts, have invented a new and useful Relay and Amplifier, of which the following is a specification.

This invention relates to a relay and am plifier for telephone and telegraph circuits. lit can be applied to wireless telephony and telegrap-hy.

The principal objects of theinvention' are to provide a relay and amplifier that will reproduce either conversation, music, or (lot and-dash signals, or in fact any sound, with a very great increase in loudness; and to provide such a device in a simple form, which by slight modifications can be used either for telegraphy or telephony and also for wireless. 1

Further objects and advantages of the invention will appear hereinafter.

Reference is to be had to the accompanying drawings, in which 1B ig. 1 is a wiring diagram showing the invention as used for receiving and amplifyi signals by wireless telegraphy;

ig. 2 is a plan of the instrument itself;

Fig. 3is a fragmentary end viewwith parts in section;

Fig. 4 is a side view partly in section, and

Fig. 5 is a wiring diagram showing a modified form. of the invention used for a telephone circuit.

Referring first to the first four figures, I have shown the invention as connected up with an ordinary wireless telegraph circuit comprising any desired form of antennae 10 connected in series with a tuner 11, the secondary of which is connected by a detector or amplifier 12 with an ordinary telephone receiver 13. This receiver may be of any ordinary kind, such for example as a Baldwin receiver which is well known on the market; T also provide the tuner with two variable condensers 14: for adjustment.

The receiver 13 shown is one which is provided with a diaphragm 20 provided at the rear with a wire 21 which is connected yieldingly with the magnet inside, but this type of receiver is not essential. ll -provide the outer side of the diaphragm with a fastening means 22 of any desired -character and to this is connected a brass pin or staple 23. With this pin is connected a flexible member, preferably in the form of a waxed silk thread 24, which at the other end is connected with a vibratory arm 25.

This arm is pivoted on adjust-able pivot studs 26 so as to avoid any looseness at the pivots. A spring 27 is used preferably to hold the arm over to one side toward an adjusting screw 28.

The actual connection of thewaxed'silk thread 2 1 with this arm 25 is made by two springs 30 and 31. The spring 31 is farthest at the rear and is directly connected with the end of the thread. Each of the springs is held to the arm 25 by a screw 32 extending into a slot in the end of the spring and holding this end fiat against the arm. They are arranged at an angle crossing each other and the inner spring 30 has its end bearing on the upper end of the arm 25. In this way the thread is held yieldingly and yet itpositively moves the arm when the diaphragm 20 moves inwardly.

To move the arm in the other direction it is provided with a connection 35 which is connected by a spring 36 with a rotatable adjusting screw 37 by means of a flexible cord 38. This cord 38 is wound around the adjusting screw 37 which screws into a post 39 and is provided with a head 40 or the like for operating it and a checknut 41 for holding it. The desired amount of tension can be applied to the arm '25 to'hold the thread 24 exactly taut and yet not unduly stretch it or strain the diaphragm 20.

The arm 25 is provided with a platinum point 42 adapted to make and break contact with a platinum point 43 mounted on an adjusting screw 44 on a frame 45. This frame is shown'as of goose-neck form and having on the opposite side an adjusting.

screw 46 for-adjusting an insulating stop?! toward and from. a projection 48 at the rear of-the arm 25.

When contact is made between the points 12 and 4:3 by the inward motion of the diaphragm 20 a current is set up in a relay circuit from the screw 44 to a buzzer 50, through a dry battery 51 back to the bracket on which the adjusting screw 28 is located, and thus back to the vibratory arm 25, which, of course is of conducting material. The buzzer I have found should be provided with a choking coil, and I have shown in this case a small incandescent lamp 52 used for this purpose. This lamp will glow I 'justed.

. audible signal.

when the current is passing, of. course, and' I I- have foundthat by this arrangement Therefore, I do not wish to be limited to all the details of construction herein shown and described,-but what I do claim is 1. In a relay and amplifier for interrupted electric circuits, the combination the buzzer will give acomplete-and perfect. with a telephone receiver connected with reproduction of any telegraphic message that may be received by the wireless appara) tile with an increase in loudness of several hundred er cent if properly tuned and adi also find that without change'of apparatus, but by more changes in adjusts 'ment and tuning, very wide rangeof wave :le'n hs can be detected and transmitted;

' he device is not limited to telegraphy however, and I have -shown in Fig. 5 a

modification in which the device can-be used for telephone pur'poses. Here I have shown the Baldwin receiver 13 as connected up with a circuit 60 which may be from a detector-or amplifier or anordinary telephone circuit. The receiver is connected with the vibratory arm 25 in the same :way as shown in Fig. 1, which transmits all sounds through atelephone circuit 61, having a battery 62 therein, to aJteIephone transformer .63 and secondary circuit 64.- provided with a telephone receiver 65. The only changes necessary in this case are a diflerent degree of adjustment and tuning, andthe provision of a carbon "terminal 67 in place of the platinum terminal 43.

' It isto be noted that in Fig. 5 'I have 'shown the instrument in what I call vertical instead of horizontal position. In this I case the springs 36 supports the weight of the arm 25 and I have found in practice that the instruments, at least those that I have actually built,act more satisfactorily in this osition than in the horizontal position. e transmission seems clearer and more nearly perfect. 1

I have-found that such an instrument is very effective in-telephony and will transmit an ordinary telephone message so loudly that it is impossible for the receiving gperator to hold the receiver65 to the ear. uch a device will transmit an ordinary conversation or music with sufiicient loudness to enable it to be heard distinctly all over a good sized room, and it will also receive wireless telephone conversatlon and trans- Although I- have. illustrated and described only two embodiments of the invention I am aware of the fact that modifications can be made therein by anyp'erson skilled in the art without departing from the sec of the invention as expressed'in the claims.

the receiving circuit/for transmitting the said arm with the vibrator part of said receiver, yielding means acting in one direction'only for constantly ulling the arm away from the receiver to eep said flexible;

means taut, a pair of terminals, one mounted to move with said arm, and the other located -in position to be engaged thereby, and a-' secondary circuit connected with said terminals and comprising means forreceiving sig-- means, a terminal on said arm, an adjusta le terminal inposition to be engaged by the first named terminal,

and acircuit connected with saidterminals. '3. In a relay and amplifier for interrupted electric circuits, the combination with a telephone receiver therein having a flexible.

diaphragm, of a pliable member connected with the center, of said diaphragm and extending from it at right an les to. its surface, a vibratory arm to whic the other end of said flexible member is connected, a spring on the other side of said arm, means for adjusting the tension ofsaid spring, a terminal on said arm, a terminal in position to be engaged by the first named terminal, and a circuit connected with said terminals.

4. In a relay and amplifier for interrupted electric circuits, the combination with a telephone receiver therein having a flexible diaphragm, of a flexible member connected with said diaphragm, a vibratory arm to which the other end of said flexible mem-' her is connected, a spring connected with said arm, means for adjusting the tension of saidspring, a terminal on said arm, a terminal in position to be engaged by the first named terminal, and a circuit connected with said terminals.

5. In a relay and amplifier for interrupted electric circuits, the combination with a telephone receiver therein having a diaphragm, of a flexible member connected with said diaphragm, a vibratory arm to which the other end of said flexible member is connected, a terminal on said arm, a terminal in position to be engaged by the first named terminal, and a circuit connected with said terminals.

7 6, A relay and amplifier for an interrupted electric circuit comprising a' telephone receiver connectedup for receiving signals, and comprising a flexible diaphragm, a waxed silk thread connected with said diaphragm,a freely pivoted vibratory arm to which said thread is connected, a

- spring connected with the opposite side only terminal thereon, a frame on which is a terminal adapted to be engaged by the terminal on the arm when the diaphragm moves inwardly, an adjustable insulated stop on the opposite side of said arm and mounted on said frame, and a transmitting circuit connected with said terminals.

phone receiver connected up for receiving signals, and comprising a flexible diaphragm, a-waxed silk thread connected with said diaphragm, a freely pivoted vibratory arm to which said thread is connected, a terminal thereon, a frame on which is a terminal adapted to be engaged by the terminal on the arm when the diaphragm moves inwardly, an adjustable insulated stop on the opposite side of said arm, and a transmitting circuit connected with said terminals.

In testimony fixed my signature.

' JAMES T. MODERMOTT.

whereof I have hereunto af- 4 25 7. A relay and amplifier for an inter- I rupted electric circuit comprising a tele- 

